A STUDY OF THE $pi$$sup +$ IN THE REACTION $pi$$sup -$ + p $Yields$ $pi$$sup +$ + $pi$$sup -$ + n AT 365 AND 432 Mev (thesis)

Technical Report · Thu Jan 17 04:00:00 EST 1963

DOI:https://doi.org/10.2172/4719064· OSTI ID:4719064

Solomon, J.

The differential distributions in energy and angle of the pi /sup +/ in the reaction pi /sup -/ + p carbon materia pi /sup +/ + pi /sup -/ + n have b een measured with a scintillation counter telescope used for pi /sup +/ detection and a magnetic spectrometer for pi /sup +/ energy determination at pi /sup -/ incident energies of 365 and 432 Mev. At each of the laboratory-system angles 20, 50, 80, and 110 l pi /sup +/ were detected in scintillation counters placed after the spectrometer. This system covered a major portion of the kinematically allowed pi /sup +/ energy spectrum. The values of T and DELTA T DELTA OMEGA for each counter after the spectrometer were determined by suspended-wire measurements. Loss in pi /sup +/ detection efficiency due to the decay of the pi was calculated. The e/sup +/ contamination in the pi /sup +/ telescope was calculated and found to agree with a measurement made at 20 l . The total cross sections at 365 Mev, 2.39 e due to uraniu 0.20 mb, and at 432 Mev, 3.98 e due to uraniu 0.20 mb, are in agreement with other recent measurements. The angular distributions in the center-of-mass system (c.m.) are d sigma /d OMEGA /sup */)/sub 365 Mev/= STA(190 e due to uraniu 16) + (10 e due to uraniu 27) cos theta /sup */! mu b/sr and d sigma /d OMEGA /sup */)/sub 432 Mev/ = STA(317 e due to uraniu 16) + (35 e due to uraniu 26) cos theta /sup */! mu b/sr. At the higher energy the forward peaking of the pi /sup +/ is less pronounced than in a previous measurement of that characteristic. Both total cross section and angular distribution can be explained to present accuracy with two models: a pi - pi interaction model and an isobaric model. The pi /sup +/ c.m. energy distributions were observed to peak at lower energies than predicted by a phase- space distribution, thereby suggesting the presence of isobar formation in the final state. An attempt was made to fit the energyspectrum data to an isobaric model using as many as three parameters. At 375 Mev moderately good fits are obtained, whereas at 432 Mev no reasonable fit to the measured energy spectrum could be found. 38 references. (auth)

• Research Organization: California Univ., Berkeley, CA (US). Lawrence Radiation Lab.
• DOE Contract Number: W-7405-ENG-48
• NSA Number: NSA-17-024274
• OSTI ID: 4719064
• Report Number(s): UCRL-10585
• Country of Publication: United States
• Language: English

Related Subjects

ANGULAR DISTRIBUTION
CROSS SECTIONS
DECAY
DISTRIBUTION
EFFICIENCY
ENERGY
ENERGY LEVELS
ENERGY RANGE
INTERACTIONS
ISOBARIC MODEL
MAGNETIC FIELDS
MEASURED VALUES
NEUTRONS
NUMERICALS
PARTICLE MODELS
PERFORMANCE
PHYSICS
PIONS
POSITRONS
PROTONS
SCINTILLATION COUNTERS
SPECTRA
SPECTROMETERS